implementation project ':app' in 'libModule' not working

Question

I need to create module in Android Studio which will contain dependency on the main project. I create new project and module, add implementation to library gradle like next:

implementation project(':app')

but when I try to sync gradle, I got next errors:

Unable to resolve dependency for ':mylibrary@debug/compileClasspath': Could not resolve project :app.

Unable to resolve dependency for ':mylibrary@debugAndroidTest/compileClasspath': Could not resolve project :app.

Unable to resolve dependency for ':mylibrary@debugUnitTest/compileClasspath': Could not resolve project :app.

Unable to resolve dependency for ':mylibrary@release/compileClasspath': Could not resolve project :app.

Unable to resolve dependency for ':mylibrary@releaseUnitTest/compileClasspath': Could not resolve project :app.

Any ideas why it happens and how to fix it?

UPDATE

here is app gradle (pretty empty)

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.pro100svitlo.testproject"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.android.support:design:28.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

and here is library gradle:

apply plugin: 'com.android.library'

android {
    compileSdkVersion 28

    defaultConfig {
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"

    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation project(':app')
}

Answer 1

Try this, works for me in similar situation. Note project is in() no space

enter code here

implementation(project(":app"))